1. Field of the Invention
The present invention relates to a thermal transfer image-receiving paper and in particular to a thermal transfer image-receiving paper comprising a fibrous paper layer having writing, typing and printing properties provided on the side of a base paper on which an image-receiving layer is not provided.
2. Description of the Related Art
Conventionally, a thermal transfer image-receiving paper provided with a foamed plastic film layer is well-known, and in such a thermal transfer image-receiving paper, transportability at the time of printing is improved and the thermal curling of the image-receiving paper is prevented by the rigidity of its base paper in addition to the cushioning properties and flatness of the foamed plastic film, and the curling of the image-receiving paper by the absorption and desorption of moisture by the base paper is further prevented by providing a waterproof layer or a resin layer on the face opposite to the side on which the image-receiving layer is provided, as disclosed in the following patent publications.
That is, Japanese Patent Application Publication No. 6-84119 discloses a heat-sensitive transfer image-receiving paper comprising a foamed plastic film laminated onto a base paper and the plastic film provided thereon with an ink absorption layer, which is provided with a waterproof layer on that side of the base paper on which the foamed plastic film is not laminated, thereby preventing curling which may occur on the whole of the paper by absorption and desorption of moisture when only one side of the base paper is provided with the foamed plastic film.
Further, Japanese Patent Application Laid-Open No. 6-15975 discloses a thermal transfer sheet wherein a base material is formed by laminating a core material for preventing curling onto one side of a porous plastic film, the base material is provided with a receiving layer on the side of the porous plastic film while the base material is provided with a resin layer playing a reinforcing role in preventing curling on the side on which the porous plastic film of the core material is not laminated.
Furthermore, Japanese Patent Application Laid-Open No. 62-198497 discloses a thermal transfer sheet wherein a base material prepared by laminating a core material for preventing curling onto one side of a synthetic paper is provided with a receiving layer on the side of the synthetic paper, while the base material is provided with a resin layer playing a reinforcing role in preventing curling on the side on which the synthetic paper of the core material is not laminated.
However, the waterproof layer or resin layer for preventing curling, which has been provided on that side of the base paper or base material on which the ink absorption layer or receiving layer is not provided in the conventional thermal transfer image-receiving papers described above, is a synthetic resin layer in a broad sense, and thus there is the problem that higher costs generally result when such layers are provided by coating such as air knife coating, roll coating and extrusion coating or by lamination such as dry lamination and extrusion lamination.
Further, the waterproof layer or the resin layer provided as described above, does not have writing properties or printing properties as possessed by fibrous papers, so there is the problem of additional costs because such layers require a special coating to endow them with typing, printing or writing properties possessed by fibrous papers for ink jet printing.